DNA constructs for the transgenes, designed and cloned by TRAM, are microinjected into pronuclei of FVB/n or B6D2F1 mouse zygotes. Injected DNA construct predominantly integrates as a single copy into the mouse genome and is transmitted through the germ line. Constructs are carefully designed to ensure that the expression of neighboring genes do not influence transgene expression and vice versa. A key feature of this transgenesis system is that it prevents head-to-tail concatemerization of the DNA construct, a common artifact in conventional transgenic methods, ensuring more predictable and stable transgene expression.

TRAM also provides identification of integration loci and assists in selecting transgenic mouse lines where the integrated transgene is positioned in intergenic regions, minimizing the risk of affecting endogenous gene expression.